This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Calling closure assigned to object property directly
If I have a class like this:
class test{
function one(){
$this->two()->func(); //Since $test is returned, why can I not call func()?
}
function two(){
$test = (object) array();
$test->func = function(){
echo 'Does this work?';
};
return $test;
}
}
$new = new test;
$new->one(); //Expecting 'Does this work?'
So my question is, when I call function two from function one, function two returns the $test variable which has a closure function of func() attached to it. Why can I not call that as a chained method?
Edit
I just remembered that this can also be done by using $this->func->__invoke() for anyone that needs that.
Because this is currently a limitation of PHP. What you are doing is logical and should be possible. In fact, you can work around the limitation by writing:
function one(){
call_user_func($this->two()->func);
}
or
function one(){
$f = $this->two()->func;
$f();
}
Stupid, I know.
Related
This question already has answers here:
Sharing var from one function to the other function in PHP Class
(2 answers)
Closed 4 years ago.
Let's say I have two different functions, and one of them has a defined variable. In the second function, I don't wanna write the same variable again, can I simply use the variable from the first function in the second one WITHOUT redefining it in the second function?
Someting like:
class example{
public function a($foo){
$foo2 = $foo + 1
return $foo2;
}
public function b($foo2){
echo "result: " . $foo2;
}
}
It's simple, you can use a property $foo2 and access it from both methods:
class example{
private $foo2;
public function a($foo){
$this->foo2 = $foo + 1
return $this->foo2;
}
public function b(){
echo "result: " . $this->foo2;
}
}
$obj = new example();
$obj->a(5);
$obj->b(); // result: 6
This question already has answers here:
Reference: What is variable scope, which variables are accessible from where and what are "undefined variable" errors?
(3 answers)
Closed 6 years ago.
I m searching for some help
It is possible to set a function with Arguments/Parameters inside another function in php? Here i have a theoretical example.
<?php
// Function with parameter/s
function funcOne($arg) {
return $arg;
}
// Parameter/s inside another function.. Possible!?
function funcTwo() {
return funcOne($arg);
}
When i try to set the parameter like this
funcOne('Alex');
echo funcTwo();
I get the following notice error
Notice: Undefined variable: arg in...
Thanks in advance :)
// Function with parameter/s
function funcOne($arg) {
return $arg;
}
// Parameter/s inside another function.. Possible!?
function funcTwo() {
return funcOne($arg);
}
funcOne('Alex');
//Call is made to function one which returned an ARG.
NOTE that here the function just returned the arg and forgot about it, now that argument is NO WHERE stored to be used
//Now here inside the functionTwo scope $arg is never defined.
echo funcTwo();
You may do the following using classes and objects
class MyClass {
public $classarg;
public function funcOne($arg) {
$this->classarg = $arg; //assigned the argument to a class variable
}
function funcTwo() {
return $this->classarg; //using the class variable to test
}
}
$myobj = new MyClass();
$myobj->funcOne('Alex');
echo $myobj->funcTwo()
You can also use global variable to achieve what you want, but I will NOT recommend to use it as Object Oriented Programming is what we should be using going forward
funcOne('Alex')is not setting a parameter, it is calling the function funcOne().
When funcOne($arg) executes, it returns the parameter $arg to the caller.
echo funcOne('Alex') will echo Alex, because that is the value returned.
After return, funcOne does not know about 'Alex' any more.
when you call funcTwo(), it executes funcOne($arg), but $arg is not defined: it has no value assigned.
function funcTwo($arg) {
return funcOne($arg);
}
Note that you should learn to use variables before making functions.
This question already has answers here:
Closed 11 years ago.
actually I wish to create a function which combine all similar functions with similar function name. For example,
<?php
//this function carry the function name I wish to create. For example:function try
a("try");
function a($arg)
{
//I wish to create function with the name carried by $arg
//but function $arg won't work
}
?>
Anyone can guide me regarding such function?
PHP is able to use variables as call-time function names so all you would have to do is
function a($arg)
{
if (!function_exists($arg)) {
throw new InvalidArgumentException(
sprintf('"%s" is not a valid function', $arg));
}
$arg();
}
If you must go down the functional path, you should do it properly
function a(Closure $callback)
{
$callback();
}
a(function() {
echo 'This is a callback';
});
or even
$b = function() {
echo 'I am an anonymous function';
};
a($b);
See http://php.net/manual/en/functions.anonymous.php
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Caller function in PHP 5?
Like this:
function foo(){
do_something();
}
function do_something(){
// How can I find out if this function was called from "foo" ?
}
Is this possible in PHP?
(Note that in my case the do_something() function is actually a class method)
You want to use debug_backtrace() (manpage)
You can use debug_backtrace, which will let you access the call stack.
function do_something(){
$trace = debug_backtrace();
if($trace[1]['function'] == 'foo'){
// called from foo
}
}
Have a look at Caller function in PHP 5?
This question already has answers here:
Calling closure assigned to object property directly
(12 answers)
Closed 9 years ago.
I have php code like:
class Foo {
public $anonFunction;
public function __construct() {
$this->anonFunction = function() {
echo "called";
}
}
}
$foo = new Foo();
//First method
$bar = $foo->anonFunction();
$bar();
//Second method
call_user_func($foo->anonFunction);
//Third method that doesn't work
$foo->anonFunction();
Is there a way in php that I can use the third method to call anonymous functions defined as class properties?
thanks
Not directly. $foo->anonFunction(); does not work because PHP will try to call the method on that object directly. It will not check if there is a property of the name storing a callable. You can intercept the method call though.
Add this to the class definition
public function __call($method, $args) {
if(isset($this->$method) && is_callable($this->$method)) {
return call_user_func_array(
$this->$method,
$args
);
}
}
This technique is also explained in
JavaScript-style object literals